Garage Band

[J]

When opening the application it seems to be looking for someone in the 
USERS>HISUSERNAME>MUSIC>GARAGEBAND folder.

I think the person who's computer I am fixing trashed these files...and 
that they are music files that belong with that application, similar to 
how iTunes stores stuff in there too..
Can these be replaced? From where?
Eventually the app itself opens OK.

Thanks.